Supernet Structures of Calcium Carbonate Mesocrystals Formed in a Blend System of Anionic/Nonionic Surfactants

A new kind of vaterite calcium carbonate mesocrystal with a self-organized supernet structure was successfully achieved in the presence of polyoxyethylene (20) sorbitan monolaurate (Tween 20) and sodium dodecyl sulfate (SDS) using the liquid-diffusion method. A well-organized two-dimensional network structure is built up successfully with a mass of sub-micrometer fanlike single crystal units. Comparative experiments showed that the mixed system of Tween 20 and SDS played important roles in the morphological control of CaCO 3 . SDS and Tween 20 can form complicated reticular micelles in aqueous solution, and the adsorption of SDS molecules onto a certain crystal face leads to the generation of the least stable vaterite. X-ray powder diffraction (XRD), FT-IR spectrometer, transmission electron microscopy (TEM), selected area electron diffraction (SAED), and field-emission scanning electron microscope (FE-SEM) equipped with energy-dispersive X-ray (EDX) were used to characterize the crystals.